He said he has been considering suicide for 20 years, and said a lack of mobility was one of the reasons he wanted to take his own life.

He added: “I greatly regret having reached that age. I’m not happy. I want to die.

"It’s not sad particularly."

Dr Goodall was able to travel to able the clinic run by Life Cycle in Switzerland after Exit International raised more than £10,000 by a crowd funding appeal as voluntary euthanasia is not legalin Australia.

The cost of dying at the clinic is around £8,000.

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GOODBYE: Dr Goodall gets a hug from Taiwanese actress during the shoot of a film about him

Considered a leading botanist and ecologist, Prof Goodall was born in Edmonton, London, in 1914.

He received his PhD from the Imperial College of Science and Technology in the capital in 1941 before emigrating to Australia in 1948, where took up a post at the University of Melbourne.

He was awarded a Doctor of Science from Melbourne University and an honorary doctorate from the Università degli Studí di Trieste in Italy.

Dr Goodall, who until his retirement in 102 was the oldest working scientist, said he hoped his very public passage to dying would help change the law in Australia.